Nonsiphoning ball cock



Jan. 5, 1954 w. H. PATTENv NoNsIPHoNING BALL cocx 2 Sheets-Sheet 1 Filed June 30, 1949 x Tx uw.: J.. 1\. I

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INVENTOR. Y wLBERT H. FATTE/y /4 TTOR/VE Y Jan. 5, 1954 w. H. PATTEN NoNsIPHoNING BALL cocx 2 Sheets-Sheet 2 Filed June 3Q, 1949 VINVENTOR. WH.. BERT H. PATTE/Y.

ATTORNEY Patented Jan. 5, 1954 UNITED STATES PATENT OFFICE NONSIPHONING BALL COCK Wilbert H. Patten, Trenton, N. J.

Application June 30, 1949, Serial No. 102,225

Claims. (Cl. 137-218) This invention relates to non-siphoning ball cocks and is directed particularly to constructions of the type frequently used in the flush 'tank of a toilet.

Many plumbing codes require the ball cock used in the ilush tank of a toilet to be provided with means for eliminating any possibility of back siphoning of water from the ilush tank or 'toilet into the water system when the pressure in the system is reduced or cut off entirely. The siphon breaking means heretofore used for this purpose have generally been designed to be applied as attachments to systems containing existing ball cocks or have otherwise operated independently of the ball cock itself. As a result such constructions have been bulky, complicated and expensive to produce and have not always been capable of use in the limited space available in small iiush tanks of modern design. Those Siphon breaking devices which have heretofore operated with the ball cock have ordinarily included ilexible members which are uncertain in their action and tend to deteriorate on long continued use.

In accordance with the present invention a new type of ball cock is provided in which Siphon breaking means are embodied directly in the ball cock so that the construction is small, inexpensive and simple in construction. This is preferably accomplished by providing 'the ball cock with a dual valve member which is movable by a iloat to control the admission of water to the flush tank from the system and is movable by gravity to admit air to the system when the pressure falls so low as to induce back siphoning.

One of the objects of the present invention is 'to provide a novel type of non-siphoning ball cock which is relatively small, simple and economical to produce.

Another object of the present invention is to provide a ball cock with siphon breaking means embodied directly in the ball cock.

A further object of the invention is to provide ay ball cock with dual valve means actuated by a float to control the flow of water from the system and actuated by gravity to admit air to the system when the pressure in the system falls so low as to induce back siphoning.

These and other objects and features of the present invention will appear from the following description thereof in which reference is made to the figures of the accompanying drawings.

In the drawings:

Fig. l is a vertical sectional view through a preferred form of ball cock embodying the present invention;v

Fig. 2 is a view similar to Fig. 1 showing the `valve portion with the parts in the position they Fig. 3 is a view similar to Fig. 2 with the parts in the position they assume when the water pressure is low and back siphoning tends to occur;

Fig. 4 is a side elevation of the construction shown in Fig. l;

Fig. 5 is a rear elevation of the construction shown in Fig. 1;

Figs. 6, 7 and 8 are horizontal sectional views taken on the lines 6 6, 'I-l, and 8-8 respectively of Fig. 1;

Fig. 9 is a vertical sectional view of an alternative form of ball cock construction embodying the present invention; and

. Fig. 10 is a vertical sectional view of a further alternative form of ball cock construction embodying the present invention. y

That form of the invention shown in Figs. 1 to 8 of the drawings is designed to be mounted in the iiush tank of a toilet and is provided with a supply pipe 2 which is surrounded by an outlet pipe 4 spaced from the supply pipe to form a discharge passage 6. The supply pipe and outlet pipe are mounted on a fitting `8 secured to the bottom of a tank I0 by means of a nut I2 and washer I4.

The ball cock is mounted on the upper ends of the supply and outlet pipes and as shown includes a head I6 having a downwardly facing shoulder I8 bearing against the upper end of the outlet pipe 4. The upper portion of the head is in threaded engagement with the supply pipe 2 as shown at 20 so that when the head is screwed down on the supply pipe the shoulder I8 is forced against the upper end of the outlet pipe 4 and serves to hold the outlet pipe in engagement with the shoulder 22 on the fitting 8. The shoulder 22 is surrounded by ribs 24 which hold the lower end of the outlet pipe in place and elevated from the collar 25 of the fitting so as to provide an outlet opening 28 adjacent the bottom of the tank and communicating with the discharge passage 6.

The upper end of the head I6 is formed with a cylindrical extension 30 having a central openl ing 32 which communicates with the supply pipe :assume when the tank is being filled; K

2 and presents an upwardly facing valve seat 34. A dual valve member 3B is formed with a cylindrical stem 38 surrounding the extension 30 on the upper end of the head I'B and provided with inwardly projecting guide ribs 40. These ribs prevent tilting of the valve member during vertical movement thereof and cooperate with extension y 30 to form Water passages 42 leading from the opening 32 in headI 6 to the chamber 44 between the head and a surrounding valve carrier or housing 46.

The valve member 36 has a lost motion connection with the valve carrier or housing and is `terioration of submerged parts.

The lower portion of the valve member 36 below the cylindrical stem 38 is formed with an outwardly projecting annular skirt 58W'vhich projects beneath the inturned annular flange 52 at the upper end of the housing 46. The upper ber should be displaced as the washer 48 is seated or for any other reason.

The upper extremities of the links 88 are turned inwardly as shown at 96 so as to project over the outwardly extending annular ange 98 on the cap 41 ofthe dual valve member 36. The

'ange 98 isV also positioned to be engaged by the bosses 92 when the housing 46 is raised to vlift the dual valve member and positively prevent sticking of the washer 48 to the valve seat 34 `when'the float rod 12 is lowered as the tank Y L empties.

surface of the skirt 50 is preierabl'y'spherical in shape or is otherwise formed to cooperate with the edge or downwardly facing surface of the flange 52 to form an air -inletvalve controlling the Vilow of air into the chamber 44 through air inlet opening 54 between the' stein 38 and the ilange 52.

The head I6 is provided with an outwardly projecting ilange 56 below the chamber 44 and spaced from the inner wallsof the housingr 46 to form a passage 58 extending to an annular recess 60 having openings 6'2 therein which cornmunicate with the inner chamber 64 of-the head.

The latter chamber communicates with passage the housing 46 andthe ahead I6 below the annular recess 60 to prevent the flow of water from the sleeve and cause it to ilow through openings 62 to the outlet passage 6.

As shown in Figs. 1,4,..5 and 7 the housing 46 is movable vertically with respect to the head I6 by means of a iloat (not shown) connected to the float rod 12. The inner end of the`rod 12 is threaded into theouter end of an arm 14 which is provided at its inner -end with a roundedfhead 16 seated within the recess A18 in the lower portion of the head I6. Lever arms 80 are pivotally connected at their outer ends to the arm 14 as shown at 82 `and are movable about the pivot 84 on head I6 as fulcrums. The inner ends of the lever arms 80 areconnected at 86 `to -links 88 which extend vertically on .opposite sides of the-housing 46. The upper portions -of the links 88 are connected to the Ahousing 46 by means of thumb screws Bil-which extend through openings in the links 88 and into upwardly-projecting bosses 92 on the housing 46. The-housing is thus movable vertically with respect to head I6 and in response to movement of the iloat and iloat rod 12. The compound lever arrangement afforded by arm 14 and lever arms 80 serves to provide the desired movement of the elements and the necessary force for closing the valve while using relatively-short links -and levers. It is therefore possible to mount all of the moving parts above the water level indicated by line 94. They are then readily available for inspection and repair and are not subject to the corrosion and de- Moreover, the links 88 impart linear' movement tothe housing 46 wherebytilting or cookingr oflthe housing is prevented. At the 'same' tlmethe spherical 'upper/surface'of the skirt 50'of"the' valve member cooperates with the edge of flange 52 to provide 'a line contact and afford effective sealing of the air inlet opening 54 even thoughthevalve-mem- Alo moved downwardv about its inner end 16.

With this construction when the level of the 'water vin'ftank Il is lowered, as by flushing the toilet,` the float descends and the float rod 12 is caused to tilt downward to the position shown in.Fig. 2 whereby the outer end of arm 14 is The lever arms 80 are thereby rocked about their fulcrums 84 so that the inner ends of the lever arms are raised to raise the links 88 and the 'housing 46 as shown. As the housing 46 moves upward the inturned flange 52 engaging the "skirt 50 of the dual valve member 36 is also raised and the valve member is then released by its lost motion connection with the housing so that it is 'freeto move upward in response to the pressure of waterin the supply pipe exerted against the washer 48 and the inner surface of the valve member 36. I'I "he pressure of the water on the inner surface of the dual valve member serves to hold the skirt 50 of the valve member against flange 52 of the housing as the housing rises and therefore air inlet opening 54 remains closed as long as the pressure `of the water in the system and issuing from the supply pipe 2 is adequate to'prevent'back Vsiphoning` Upward movement of the housing also serves to move the bosses 92 into engagement with the flange 98 on cap 41 so 'as'to positivelyraise thervalve member 36 and overcome any tendency of the valve to stick after long inaction.

`When the valve member 36 is raised water 'flows from the su'pplypipe 2 downwardly through the water passages 42 about the cylindrical extension'of the head I6 to the chamber 44. From the latterchamberv the Water flows through passage 58 to openings 62 andinto the inner chamber 64 of head I6 whence it flows through pas- Sage 66 to' the vLipper end of outlet passage 6 between the supply pipe 2 'and outlet pipe 4. From theV outlet pipe 4 the water issues into the tank 'I0` through outlet opening 28 adjacent the bottom of the tank.

In 'this way the discharge of water into the tank takes place quietly and serves to rell the tank as soon a's the tank outlet valve is closed. The parts are further designed and proportioned to insure consistent andquiet operation of the ball cock and for this purpose the cross sectional area of the water passages 42 about the cylindrical extension 30 of the head, the passage 58 at 4the bottom of chamber 44, and the openings 62 leading to the inner chamber 64 of head I6 are each made'substantially equal to the cross sectional area of the opening 32 of the supply pipe 2`. The pressure in chamber 44 when the valve member 36 rises is therefore maintained the .innerchamber 64 of the head to the outlet sage and outlet 28 are larger than the cross section of the supply pipe and openings 62 so that there is a continuous drop in pressure allowing free flow of water from the ball cock to the tank without noise or back pressure.

As the tank refills due to normal operation of the ball cock in supplying water to the tank, the loat serves to move the rod '|2 upward whereby lever arms 80 are tilted to draw the housing 46 downward. The flange 52 on the housing bears against the skirt 50 of the dual valve member to draw member 36 downward until the washer 48 is pressed against the valve seat 34 on the tubular extension 30 of the head |6. The supply of water to the tank is thus cut off and the elements are returned to the position shown in Fig. l, with a minimum of movement of the float and float rod '|2. A stop member may be formed on the head I 6 as shown at |00 to limit downwardly tilting of the lever 14 while upward movement is limited by closing of the valve member after or degrees of movement. Rapid and effective closing of the valve is assured even when the water pressure is high due to the power exerted by lever 'I4 through the lever arms 84. Moreover, the movement of the housing 46 and valve member 36 is rectilinear since links 90 are pivotally connected to the housing 46 and the guide ribs 68 on head I6 and ribs 40 on the interior of the valve member maintain the elements in alignment and overcome any tendency for the elements to tilt. The spherical upper surface of skirt 50 further assures an air tight seal between the valve member and flange 52 of the housing even though cooking of the valve member should occur.

In the event the water pressure in the system should fall dangerously low or should be cut off altogether while the toilet is flushed and the tank ball is lowered, the lost motion connection between the housing or valve carrier permits the dual valve member to move by gravity from the position shown in Fig. 2 to the position shown in Fig. 3 wherein the skirt 50 is spaced from the inturned ilange 52 andthe air inlet opening 54 is opened to admit air to the system. At such times air ows through opening 54 to chamber 44 and thence upward about the cylindrical extension 30 of the housing to the supply vpipe 2 whereby siphoning of water from the tank is prevented. It will further be noted that the air entering chamber 44 through inlet 54 is directed by the skirt 50 toward the passage 58 between flange 55 and the inner walls of the housing I6. In this way back surging of Water from the tank to chamber 44 and into the system through supply pipe 2 is prevented even under the most adverse conditions. Thereafter when the pressure in the system rises the valve member 36 is again raised by pressure applied to the inner and lower surface thereof so that the skirt 50 closes the air inlet opening 54 and the valve will operate in its usual and intended manner as described above.

In that form of the present invention illustrated in Fig. 9 the supply pipe is shown at |02 and is surrounded by the outlet pipe |04. A head |06 is threaded onto the supply pipe and formed with a cylindrical extension |08 presenting an upwardly facing valve seat |I0. -A casing ||2 is threaded onto the head |06 and formedwith a chamber 4 surrounding the tubular extension |08 of the head. Passages l |6 extend from chamber ||4 to the outlet passage ||8 between the supply pipe |02 and outlet pipe |04.

The dual valve member shown in Fig. 9 isshown at and includes a stem |22 which extends downward about the tubular extension |08 on the head |06, being guided in its movement by the ribs I 24 which project outward from the tubular extension and define passages extending from the upper end of the supply pipe to chamber I4. The valve member is provided with an inner downwardly facing washer |26 for engaging the valve seat I I0 and with an upwardlyy facing right angle shoulder |28 which is engageable with'the downwardly facing spherical surface |30 of a valve carrierpiston member |32 to form an air inlet valve.

The piston member is slidable within the tubularguide portion |34 of the casing ||2 and is :provided with a packing |36 for preventing leakage of water upward past the piston member from chamber ||4. The central portion of the piston member is formed with an air passage |38 surrounded at its lower end by the valve surface |30 and opening at its upper end into the cross slot |40 which communicates with the air above the water line maintained in the tank. A pin |42 extends across the passage' |38 and through the ring portion |44 formed on the rtop of the valve member. The opening in ring portion |44 is of substantially larger diameter than pin |42 so that a lost motion connection is provided whereby vthe valve member is movable relative to the piston member to open and close the air valve defined by spherical surface |28 on the valve member and surface |30 on the piston member.

The piston member and valve member may be raised and lowered by any suitable means for controlling the flow of water into the tank where the ball cock is used. As shown the float actuated rod |46 is connected tothe arm |48 pivoted at |50 onvthe casing II2. A link |52 connects arm |48 to the longer end of lever arm |54 as shown at |56 whereas the shorter end of arm |54 extends into a slot |58'on the upper extremity of the piston member |32.' The lever arm |54 is pivotally mounted at |60 on the casing ||2 as a fulcrum so that when the float rod moves downward the piston memberis raised and when the float rod moves upward the piston member is moved downward. f

With this construction emptying of the tank causes' the float rod to `tilt downward raising the piston member so as to lift the valve member |20. The initial upward movement of the piston member does not positively lift the valve member because of the lost motion afforded by the loose connection between pin |42 and the ring portion |44 of the valve member. However, the valve member is released to rise under the action of water pressure exertedon washer |26 and the inner surfaces of the stem |22 of the valve member. The valve member therefore follows the piston member as it rises and the air inlet valve isheld closed by the pressure of water within the chamber ||4.

If` the water pressure should fall while the piston member and valve member are raised the valve member -will at once fall by gravity to the extent permitted by the pin and ring portion and sufficiently to admit air to chamber I4 through thepassage |38and the air inlet valve formed by shoulder |28. and spherical surface |30. In this way back siphoning is prevented by the admission of air to the system whenever the pressure yfalls low enough. to allow rthe, valve member tofall as the valve opens.

The construction shown in Fig. 10 is essentially the same in principle as those forms of the inventionllllustrtd inFigsfllan-d 9. In Fig. 10 the vdual valvememberili! is mounted within a valve 'Jca'rrler orlpistonmember |64 actuated by thebell crank lever- |66.and oat rod |58. The form of the'dual valve member is generally similar to that of Fig.v 1 vand it.is provided with a lost motion connection with thepiston member so that it will be actuated by the piston member during normaloperation of the device to move washer |10 into Yand out of engagement with the valve seat at the upper end of they tubular extensionv|`|2 of the'head` :|14 on supply pipe |16. When the pressure in the system falls or is cut oft` thelost motion connection allows the valve member to move'with respect to the piston member under the action of gravity to open the air inlet opening between skirt |18 of the valve member and flange^|80 of the piston member. Air can then enter the'system through passage |82 about thefcap |84 so as to flow through the air inlet opening about the stem of the valve member.

The skirt |18 of the valve member |62 is shown in` Fig. l as having a flat upper surface for engaging the Hat, downwardly facing surface of flange' |80 in acting as an air inlet valve. However, it will befapparent that the particular form of the valve forming surfaces of the dual valve member and parts cooperating therewith may b'e varied considerably as exemplied by the typical constructions which have been shown in Figs. 1, 9 and l0. It will also be evident that the various forms of the invention embody other parts which may be interchanged or varied in that the operating levers for raising and lowering the Ahousing or piston members may be substituted one for another.

In each of the forms of the invention a refill tube v|86 communicates with the chamber beneath the valve member as shown most clearly in Fig.' 1 and in` each case there is also provided a stop means for limiting downward movement of the float rod and float. Conventional elements of this character may be used or added to the constructions shown and each of the elements of the assembly may be altered in form, construction and arrangement to adapt the invention to specific uses and applications or to preferred manufacturing methods. In view thereof it should be understood that those forms of the invention shown in the drawings and described above `are intended to be illustrative only and are not intended to limit the scope of the invention I claim:

l. A ball cock comprising a member formed for attachment to va liquid supply pipe and having a valve seat thereon, a housing forming a chamber communicating with said valve seat and provided with Va passage for the discharge of liquid from said supply pipe, means providing an air inlet opening communicating with said chamber, a dual valve member loosely carried by and vertically movable with respect to said housing and having two oppositely facing surfaces held in ilxed relative positions one of which is movable into andout of engagement with said valve seat to control the admission of liquid to said chamber from said supply pipe and the other of which is movable in response to the pressure of liquid in said chamber to close said air inletopening and movable by gravity to open said opening,V said housing being movable with respect to said member and oat actuated means for moving said housing.

2. ..ball cockcomprsing a headformed for attachment to a liquid supply pipe and having a valve seat thereon, a housing movable with respect to said head and having a chamber therein communicating with said valve seat and provided with a passage for the discharge of liquid from said supply pipe, means providing an air inlet opening communicating with said chamber, a dual valve member loosely carried by and movable with respect to said housing to open and close said air inlet opening, said valve member having a portion thereon engageable by the housing for positively moving the valve member into engagement with said valve seat on downward movement of the housing, the valve member being movable upward with the housing and vout of engagement with the valve seat in response to the pressure of liquid in said chamber.

3. A ball cock comprising a head formed for attachment to a liquid supply pipe and having a valve seat thereon, a housing surrounding said head and having a chamber therein communicating with said valve seat and provided with a passage for the discharge of liquid from said supply pipe, said housing being movable with respect to said head and formed with an air inlet opening in the upper portion thereof communicating with said chamber, and a valve member located within said housing and vertically movable with respect thereto land in response to the pressure of liquid insaid chamber toa position in which it closes said air inlet opening, said valve member being movable by gravity and with respect to said head to open said air inlet opening, and iioat actuated means for raising said housing to a position in which said valve member may move by gravity to a position in which said air inlet opening is open,

4. A non-siphoning Iball cock comprising a head formed for attachment to a liquid supply pipe and having a valve seat thereon, a member slidable with respect to said head and cooperating therewith to form a chamber communicating with said valve seat and provided with a passage for the discharge of liquid from said supply pipe, means providing an air inlet opening communicating with said chamber, a dual valve member carried by said slidable member and movable with respect thereto to a normal position in response to normal pressure of water in said chamber and to an air inlet opening position in response to sub-atmospheric pressures in said chamber, said valve member when in said normal position being movable with said slidable member into and out of engagement with said Valve seat and float actuated means for actuating said slidable member.

5. A non-siphoning ball cock comprising a head formed for attachment to a liquid supply pipe and having a valve seat thereon, a housing surrounding said head and having a chamber therein communicating with said valve seat and provided with a passage for the discharge of liquid from said supply pipe, said housing being movable with respect to said head and formed with an air inlet communicating with said chamber, iloat control means connected to said housing for raising and lowering the housing with respect to said head, a valve member located within said housing and movable to raised and lowered positions with respect thereto, said valve member when in raised positionv serving to close said air inletopening, and when in lowered position serving to open said air inlet opening, said valve member being responsive to the pressure :of liquid in' .said .chamber and movable ,under normal liquid pressure to said raised position and movable under sub-atmospheric pressure by gravity to said lowered position, said valve member further being movable with said housing into and out of position to engage said valve seat in response to movement of said ilo-at actuated means.

6. A non-Siphoning ball cock for a flush tank comprising a hea-d formed for attachment to a supply pipe and designed to be located above the level of water in the tank, said head having a valve seat thereon, `a valve carrier having an air inlet opening therein communicating with said valve seat, float actuated means for moving said carrier with respect to said head, and a dual member movable into and out of engagement with said valve seat and into and out of position to close said air inlet opening, said dual valve member having a lost motion connection with said valve carrier permitting relative movement of the carrier and valve member, said valve member being positively movable with said carrier into position to engage said valve seat and being movable by gravity and with respect to the carrier into position to open said air inlet opening.

7. A non-Siphoning ball cock for a ush tank comprising a head formed for attachment to a supply pipe and designed to be located above the level of Water in the tank, said head having a valve seat thereon, a valve carrier surrounding said head and cooperating therewith to form a chamber having a discharge opening and `communicating with said valve seat, said valve carrier having an air inlet opening therein, float actuated means for moving said carrier with respect to said head, and a dual valve member movable into and out of engagement with said valve seat and into and out of position to close said air inlet opening, said dual valve member having a lost motion connection with said carrier permitting relative movement of the carrier and valve member, said valve member being positively movable with said carrier into position to engage said valve seat and being movable by gravity and with respect to said carrier into position to open said air inlet opening.

8. A non-siphoning ball cock for a flush tank comprising a head formed for attachment to a supply pipe and designed to be located above the level of water in the tank, said head having a valve seat thereon, a valve carrier in the form of a housing slidably movable in opposite directions and with respect to said head, said carrier cooperating with the head to form a chamber having a discharge opening and communicating with said valve seat and having an air in'let therein communicating with said chamber, oat actuated means for moving said carrier with respect to said head, and a dual valve member movable into and out of engagement with said valve seat and into and out of position to close said air inlet opening, said dual Valve member having a lost motion connection with said carrier permitting relative movement of the carrier and valve member, said valve member being positively movable in one direction with said carrier into position to engage said valve seat and being movable by gravity in the opposite direction and with respect to said carrier into position to open said air inlet opening.

9. A non-siphoning ball cock comprising a head having a. valve seat thereon and formed for attachment to a supply pipe above the level of water in the tank, a dual valve member having one portion thereof movable into and out of engagement 1 il with said valve seat, a valve carrier surrounding said valve member and cooperating with said head to define a chamber communicating with said valve seat and provided with a discharge outlet, and float actuated means connected to said valve carrier for moving said carrier in opposite directions with respect to said head, said carrier having an air inlet opening therein communicating with said chamber and positioned to be closed by another Iportion of said valve member, there being a lost motion connection between the valve member and the valve carrier serving to urge the valve member toward said valve seat on movement of the carrier in one direction and to permit movement of the valve member by gravity and with respect to said carrier into position to admit air to said chamber through said air inlet opening on movement of the valve carrier in the opposite direction.

10. A non-siphoning ball cock for a flush tank comprising a head having a valve seat thereon and formed for attachment to a supply pipe above the level of water in the tank, a Valve member movable into and out of engagement with said valve seat and having a cylindrical portion surrounding said head and guided for longitudinal movement with respect thereto, a housing forming a chamber surrounding said head and communicating with said valve seat, said chamber having a discharge opening therein and being formed with an air inlet opening, said housing being movable with respect to said head by float actuated means, said housing being guided for longitudinal movement with respect to said head and valve member, said valve member having a part engageable with said housing to positively move the valve member toward said valve seat on movement of the housing in one direction and having another part engageable by the housing to positively move the valve member away from the valve seat on movement of the housing in the opposite direction, said parts being so spaced as to provide a lost motion connection between said housing and valve member, said valve member being movable with respect to said housing to open and close the air inlet opening in the housing.

WILBERT H. PATTEN.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 645,662 Emery Mar. 20, 1900 1,503,433 Shaffer July 29, 1924 2,046,792 Schmiedeknecht July 7, 1936 2,086,637 Price July 13, 1937 2,153,904 Wnson Apr. 11, 1939 2,181,900 Langdon Dec. 5, 1939 2,247,525 Sherwood July 1, 1941 2,259,984 Anderson Oct. 21, 1941 2,270,910 Svirsky Jan. 27, 1942 2,290,145 Owens July 14, 1942 2,294,785 Langdon Sept. 1, 1942 2,299,706 Svirsky Oct, 2o, 1942 2,324,084 Horner July 13, 1943 2,367,951 Lewis Jan. 23, 1945 2,569,017 Owens Sept. 25, 1951 2,607,364 Smith Aug. 19, 1952 FOREIGN PATENTS Number Country Date 211,511 Germany of 1909 

